The SS AMERICAN MARINER is ready to bunker with drafts of FWD 13'-10", AFT 16'-04". After all bunkers are on board, soundings indicate the tonnages shown in table ST-0179 below. Use the white pages of The Stability Data Reference Book to determine the free surface correction.
• Use the white pages free surface tables for the SS AMERICAN MARINER, not the curves or examples in the gray pages. • Remember that free surface moments are proportional to the weight of liquid in each slack tank; centerline and port/stbd pairs are handled differently. • The total free surface correction (FSC) is found by summing the free surface moments of all slack tanks and then dividing by the vessel’s displacement at the final drafts.
• From the table ST-0179, which of these tanks are likely to be slack (not pressed full, not empty), and therefore contribute to free surface? • Once you’ve identified those tanks, how do you use their individual tonnages to enter the white-page tables and obtain a free surface moment (or equivalent) for each tank? • After you combine the free surface effects of all contributing tanks, how do you use the ship’s displacement at 13'-10" FWD and 16'-04" AFT to turn that combined effect into a correction in feet of GM?
• Verify you are using the correct SS AMERICAN MARINER data pages and the correct column for bunkers/DB or deep tanks. • Confirm the displacement you divide by is for the final condition after bunkering, taken from the appropriate hydrostatic table for the given mean draft. • Double‑check that port and starboard tanks of equal loading are either treated as a pair (no list, but free surface counted twice) or according to the specific instructions in the book’s example problems.
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